An example of an electronic device employing a touch panel is described in Patent Documents 1 and 2. As known widely, a touch panel is overlaid on a display device (e.g., a liquid crystal display) for displaying an image. Here, in the touch panel, an integrated construction consisting of a protection glass, a sensor (glass, film), and a touch panel controller is referred to as a touch panel module. Further, a construction consisting of a touch panel module and a display device is referred to as a touch panel unit.
In a portable phone described in Patent Document 1, in order that when a user grasps the device in whatever manner, key operation should be achieved easily, the part of the device grasped by the user is detected by a sensor and then the display region is shifted depending on the situation. On the other hand, in a display apparatus with touch panel described in Patent Document 2, in order that erroneous detection in the touch panel caused by driving of the display apparatus should be avoided, each sensor electrode of the touch panel is selected one by one and then contact of a conductor (a finger) at the position corresponding to the selected sensor electrode is judged.